Drafting instrument.



C. G. ROW.

DRAFTING INSTRUMENT.

APPLICATION FILED sPT.2I, 1914.

Patented June 8, 1915 2 SHEETS-SHEET I.

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Patented June 8, 1915.

2 SHEETS-SHEET 2.

\ A n@ K CHARLES e. Row, orsan sancisce, CALIFORNIA.

DEAFTING'INSTEUMENT.

Specification of Letters 'raten-t.

Patented June 8, 1915.

Application filed September 21,' 1.911,1.. Serial No. $63,987.

T0 all whom it may concern:

Be it known that I, CHARLES G. Row, a citizen of the United States, and a resident of the city and county of lSan Francisco, State of California, have invented a new and useful Improvement in Drafting Instruments, of which the following is a specification.

My invention relates to drafting instruments wherein interchangeable blades are slidably mounted to each other and operate to present a series of straight edges arranged parallel and transversely to each other on different portions of a drafting board; and. the objects of my invention are first, to provide an improved drafting instrument for drawing lines parallel to either edge of the drafting board; second, to provide an improved drafting instrument adapted to be secured to either edge of a drafting board or a pad of paper and the like; third, to provide an instrument of the character described lby means of which circles of any given radius may be drawn; fourth, to provide means whereby the center of the circle describing means may be sh'ftedto various portions of the drafting board; and

. fifth, to providea drafting instrument of peper nadthe character described wherein thel parts are interchangeable.

I accomplish these several featuresl by means of the device disclosed in the draw-I ings forming a part of the present specification wherein like characters of reference are used to designate similar 'parts throughout the said specification and drawings, and in whichv Figure l is a plan view of the device secured to a drawing board, the dotted lines being used to indicate possible positions of the extensible circle describing or compass blade. Fig. 2 is a sectional view taken on line 2-2 of Fig. 1 vof the drawings, disclosing the manner in which the device may be secured to a draftingboard or drawing Fig. 3 is an enlarged'sectional viewtaken on line 3 3 of Fig. 1 of the drawings disclosing the ymanner in vwhich the main blade may be secured to the drawing board or a drawing paper pad. said sectional view also disclosing the groove,.having one overhanging edge, by means of which the double lipped runner' on .the first movable blade is slidably retained in said groove. ig. eis. a sectional view taken on line 4-4 or F1a 1', disclosing the thumb nut in the runner of the first movable blade by means of which the said runner is elevated so as to impinge one of the lips thereon tightly against the under side of the overhanging edge in the groove of the main or stationary blade, thereby preventing the movement of the said first movable blade. Fig. is a sectional view taken on line 5-5 of Figs. 1 and 6, disclosing the manner in which the circle describing or compass blade is slidably connected with the pivotal member which is in turn slidably secured to the second movable blade. Fig. 6 is a sectional yiew taken on line 6-6 of. Fig. l, disclosing `the manner in which-the compass blade is slidably connected with the pivotal meinber that is in turn slidably mounted upon the second movable blade. Fig. 7 isl a typical sectional view of the grooves in the blades and the runners slidably mounted therein.

Referring to the drawings the numeral 1 is used to designate a drafting board, to the lower or near edge of which is secured the main or stationary blade 2 by means of suitable clamps 3 which may be tightened by the thumb screws 4. The'station'ary blade 2 is provided throughout the length thereof with a longitudinal groove 5 having an overhanging lip 6 on one side and throughout the length thereof- A runner 7, having a longitudinal lip-8 .on eaoh lower side thereof, is slidably mount- 5 and one of the lips yed within .the groove 7 is arranged to lie 8 on the said fumier yunder the over ian ing edge 6 of thev said groove 5 s o thatw ile the said runner 7 1s vfree to slide in the groove it is retained therein by means ofthe said edge 6.

A thumb nut 9 is screwed into the runner 7 and is arranged to elevate the said runner 7 and tightly `irnpinge one lip 8 thereon tightly against the under side of the overhanging edge 6 of ythe groove 5.and thereby reyept the movement of the said runner in he4 said groove. lnasninch as there is only one overhanging ,edge on. the groove 5 ,to engage one of the lips 8 on the runner 7 it is evident that the said runner 7 may be easily disengaged andremoved from the groove o and edge 6 thereof by raising the Outward and of a Second blade 12 which is rigidly secured thereto, which movement will raise that side of the said runner 7 yopposite the edge 6 of the groove 5 .until that side clears the groove. The second blade 1 2, is also provided with "lio a groove 5 'milar to the grooyedin the blade 2 and havig one overhaliginI 'edge 6 and Within said groove is slidablyfr'nounted a second runner 14 similar in construction and operation to the lirst mentioned runner.

To the second mentioned runner is rig- ',"idly-securedr'r thirdblade 16 which is also provided with construction to the grooves in the blades 2 and 12. Within the third groove 5 is slidably 'mounted a comparatively short double lipped runner 17 having 'two thumb screws 18 secured. thereto by means of which a double slotted plate 19 is rigidly secured to Ithe said runner 17. lA pivotal member 20 is pivotally mounted upon the plate 19 by means of an open rivet 21 and to an extension 22 of the said pivotal member 2O is slidably secured what I term a compass blade 26. I

The fourth or compass blade 26 is pivotally and slidably secured tothe extension 22 of the pivotal membe'r21 by means of a bolt 24g which is arranged 'to engage one of the apertures 23 of the said extension'22 and4 al slot 25 in the -compass blade 26.

All of the blades are provided 4with suitable graduations on'both sides thereof so that a line of any.' given length, within the range of the drawing paper, may be drawn.l

The compass blade 26A is 'provided with a series of apertures 27 through which'a pencil may be inserted so :that the said pencil Will describe an arc when the compass blade 26 is partially rotated upon its pivotal point 21. v 4

The apertures `27 are provided at regular intervals of one inch which coincide Withthe one inch graduations on the blade 26 so that the number opposite the hole in which the pencil is inserted vvillv indicate the length of the radiusl of thi;I arc described in inches. If it isl desired to describe 'an arc Whose radius includes a fraction o f an inch the 1 same may be laccomplished by loosening the ,g as all of the runners are interchangeable and will t any one of the grooves in any one of the movable or the stationary blades, it is evident that the vcompass blade 26 may be slidably mounted upon the second or transverse blade 12 or the main blade 2.

By eliminating or removing the blade 16 ,and attaching the compass blade 26 to the transverse blade y12 an instrument will be .a third groove 5 similar in.

or stationary provided nhich will accomplish lall of the features of a T-square, triangles and compass.

.By lsetting the compass blade 26 at right angles to the blade 12 and moving the said blade 26 up or down lines may be drawn parallel to the main blade 2, and by moving the transverse blade/12 on the blade 2 a series of parallel lines may be drawn transversely to the first mentioned parallel lines.

Also, oblique lines `and arcs may be drawn by means of the compass blade 26.

The compass blade may be rigidly secured i at any angle or position b y means of the thumb nut 30 which operates inthe arcuate slot 31 of. the pivotal member 20 and is secured to the plate 19. By securing the compass blade 26 at any given angle and Siding the same in the groove of the blade 16 an efficient and practical section liner may be provided :is the movement of the said compass blade 26 may be regulated by the graduations on the blade 16. A

'It is obvious from ythe `foregoing that I have provided an improved drafting instruvment adapted to draw lines parallel and transversely to each other and also adapted to describe arcs of any given radii.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent isl 1. A drafting instrument comprising a stationary bladeadapted to be secured to a drafting board or pad; a second blade slidably'mounted upon the first mentioned blade and' arranged transversely thereto; a third blade slidably mounted upon the second mentioned blade and arranged to lie parallel With the first mentionedblade; a runner slidably mounted upon the third mentioned blade; means adapted to prevent the movement of the runner on the third mentioned blade; a

.pivotal member secured to the runner; and .a fourth blade having a series of apertures arranged at regular intervals therein and slidably secured to the pivotal member.

v2. A drafting instrument comprising a stationary blade having graduations thereon and a longitudinal groove therein; a second blade having graduations and a longitudinal groove therein and a runner rigidly secured thereto, said runner .being adapted to be slidably mounted within the groove of the y first mentioned blade; a third blade having graduations thereon an d a longitudinal groove therein and a runnerv rigidly secured thereto and adapted to slidably engage the groove inthe first and second mentioned blades; means adapted to prevent the move- Vment of the last mentioned runner` Within the groove; a plate adapted to be secured to the last mentioned runner; a lpivotal member pivotally secured to the plate and apertured on its pivotal center and having an extension thereon; and a fourth blade slidably secured to the pivotal member and having gradu ations thereon and a series of apertures arranged at regular intervals therein.

8. A drafting instrument comprising a stationary blade having graduations thereon and a longitudinal groove therein, said groove having an overhanging lip 'throughout the length of one side thereof; means l adapted to secure the said blade to a drafting board or pad;a second blade having graduations thereon and a longitudinal groove therein similar to the first mentioned groove; a runner secured transversely to the second blade and having a lip on each side of the lower edge thereof, said runner being arranged to engage the groove in the first mentioned blade; a third blade similar to the other blades; arunner similar to the other runner and secured transversely to the third mentioned blade and adapted to slidably engage the groove in the first and second mentioned blades; means secured to each runner and adapted to secure the said runner against movement in the groove; a third runner similar to the other runners and adapted to slidably engage the groove in any one of the other blades; a plate detachably secured to the .last mentioned runner; a pivetal member detaehably secured to the plate and having an extension thereto; and a` fourth blade having graduations thereon and apertures .arranged at regular intervals therein, said blade being slidably connected to the extension of the pivotal member.

4 A drafting instrument comprising a stationary blade having graduations thereon and a longitudinal groove therein; means adapted to secure the blade to a drafting third runner adapted to slidably engage any oneof the grooves; means secured to each runner and adapted to prevent the movement of the said runners in the grooves; a plate detachably and slidably secured to the third runner; and 'a fourth blade having graduations thereon and apertures arranged at regular intervals therein, said fourth mentioned blade being slidably and pivotally attached to the plate secured to the third mentioned runner; and means adapted 'to secure the last mentioned blade at various angles to the third mentioned blade.

ln witness whereof l lliereunto set my signature in the presence of two subscribing Witnesses.

, CHARLES G. ROW. lVitne'sses:

IRENE DowNEY, JAMES F. MCCUE. 

